---
id: "MAL-2026-17180"
kind: "package"
aliases: ["MAL-2026-17180"]
title: "Malicious code in my-private-pkg (PyPI)"
severity: "critical"
cvss: null
epss: null
exploited: false
status: "open"
category: "package"
products: [{"name": "my-private-pkg", "fixed": [], "affected": "= 99.1.1; = 0.1.1; = 99.11.2", "ecosystem": "pypi"}]
ecosystems: ["pypi"]
tags: ["malicious", "package"]
not_affected_if: []
published_at: "2026-09-25T00:08:08+00:00"
first_seen_at: "2026-10-26T20:51:58+00:00"
updated_at: "2026-10-26T21:10:31+00:00"
sources: [{"source": "osv-malicious", "url": "https://osv.dev/vulnerability/MAL-2026-17180", "first_seen_at": "2026-10-26T20:51:58+00:00"}]
---

# Malicious code in my-private-pkg (PyPI)

## Affected

- pypi:my-private-pkg affected = 99.1.1; = 0.1.1; = 99.11.2 fixed ?

## Timeline

- 2026-10-26T20:51:58+00:00 osv-malicious https://osv.dev/vulnerability/MAL-2026-17180

## From the sources

Version 99.1.1 of my-private-pkg executes a custom setuptools install hook while a wheel is built. The hook launches my_private_pkg/index.py, which collects the current username, working directory, hostname, resolved local IP address, operating system, and machine architecture, then attempts to POST the resulting JSON to a hard-coded Webhook.site request collector. Dynamic analysis observed the wheel build spawn this script followed immediately by network activity. The package's public metadata describes it only as a private Python package and does not disclose the collection or transmission.

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_-= Per source details. Do not edit below this line.=-_

## Source: amazon-inspector (d8008c5637dfae2dfc4162f1dd5152c5e90e03b0fc8593fda5055f44e9745b22)
setup.py registers a custom install command (PostInstallCommand) that runs my_private_pkg/index.py automatically on `pip install`. That script gathers installer-side identifiers — os.getlogin(), socket.gethostname(), local IP address, os.getcwd(), platform.system() and platform.machine() — and POSTs them as JSON to a hardcoded collector URL at https://webhook.site/d4d1b01b-708a-40b9-b8c8-187eeecafeed. A duplicate of the exfiltration payload is shipped as vercel_runtime_python/index.py, and vercel_runtime_python/__init__.py contains the same PostInstallCommand wiring referencing my_private_pkg/index.py; the module name mimics Vercel's Python runtime. The package name and the internal vercel_runtime_python module name are consistent with a dependency-confusion lure targeting an internal `my-private-pkg` name and Vercel's runtime namespace: the only on-install effect is a reconnaissance beacon to an attacker-controlled webhook.site endpoint identifying the host that mistakenly resolved the public name.

## Source: kam193 (b9272fe1642ca0e3b8b1cfcf930ca69b08119ed258cdc760f9ad8a014b76767b)
Installing the package or importing the module exfiltrates basic information about the host, and the package has no other purpose.


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Category: PROBABLY_PENTEST - Packages looking like typical pentest packages, but also anything that looks like testing, exploring pre-prepared kits, research & co, with clearly low-harm possibilities.


Campaign: GENERIC-standard-pypi-install-pentest


Reasons (based on the campaign):


 - The package contains code to exfiltrate basic data from the system, like IP or username. It has a limited risk.


 - The package overrides the install command in setup.py to execute malicious code during installation.

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